Unable to make holes using boolean modifier
The problem with your file is that you have a lot of disjoint geometry and non volume geometry.

Observing a small section of the model shows a problem: A, B, and C are disjoint. (Not attached to eachother) and they therefor don't form a watertight (Manifold) volume. Also B and C even have Polygon normals  that go in opposite directions. Which you can tell by the color differences in the mesh. Purple vs Grey.



I'm sure if you study the model further, or come back to it when you have more experience with the Boolean Modifier you will see immediately all kinds of things that make it impossible to do what you are trying. I suggest a different approach, it's easier I think.



Here's a demonstration of what my approach would be to this. Use the Screw Modifier and a profile as the rotation shape. A benefit of this is you can easily change the number of vertices on the circumference of the object, by changing the 'Steps' value.



I've also used the Array Modifier to make a radial array, this arrays an object (The extruded Circle) around a fixed point (an Empty). The Empty's rotation influences the rotation of the repeated object.



Then finally you can add the boolean modifier and hide the Circle object.